Experts Say These 11 Popular Garden Plants May Be More Toxic Than You Realize

This sturdy annual, which grows as a perennial in warm climates, comes in many different colors from pure white to hot pink and orange. It doesn’t mind drought and poor soils, so it’s a popular choice for landscape beds and containers. It’s a favorite of pollinators, too.

However, the flowers, fruits, leaves, and sap contain terpenes, which can cause vomiting, diarrhea, dilated pupils, and labored respiration in people and pets. The leaves and sap of lantana also may cause contact dermatitis in sensitive people.

Castor bean is a fast-growing ornamental shrub with large leaves and bright red spiny seed capsules. It’s an intriguing-looking plant that many people grow as an annual.

Unfortunately, all parts of this plant, including the leaves, flowers, seeds, and sap, are deadly toxic, containing ricin, a phytotoxalbumin, and ricinine, an alkaloid. The plant is lethal if only a few seeds are ingested, and it also causes contact dermatitis when the foliage is handled.

In pets, kidney failure, convulsions, and death can occur. This is a plant best not grown if you have kids or pets.

There are more than 100 species of lilies and hybrids, including Asiatic lilies, stargazer lilies, Easter lilies, and Oriental lilies; unfortunately, all Lilium plants are toxic to cats. All parts of the plant are dangerous, and even small amounts can cause severe injury to the kidneys. Even drinking the water containing a lily you’ve cut from your garden or cats grooming lily pollen off their fur may cause serious health concerns.

Because of the severity of the risk, it is recommended you do not grow lilies in your garden (or display them as cut flowers indoors) if you have cats. They are not toxic to dogs, though be aware that any plant material that’s ingested in large enough quantities can cause GI upset, says Dr. Wismer.

These beautiful spring flowers come in brilliant pinks, blues, purples, and white and have a delightful scent. Hyacinths are a lovely low-maintenance way to add much-needed spring color to your landscape.

However, all parts of the plant contain toxic alkaloids such as lycorine. The hyacinth bulb itself contains the highest amount of the toxin. The plants also may cause skin irritation in some people. Ingestion may cause stomach cramps, salivation, vomiting, and diarrhea in people and intense vomiting, diarrhea, and tremors in pets.

This spring-flowering plant is one of the first to appear after a long winter. With its cheery, white or yellow nodding flowers, daffodils are a great addition to the spring garden. But, like hyacinths, all parts of the plant are toxic, with the bulb containing the most toxins, such as lycorine and other alkaloids. It also may cause contact dermatitis in some people. If ingested in large quantities, it may cause low blood pressure and cardiac arrhythmias. In pets, it causes similar symptoms, including convulsions and cardiac arrythimas.

There are thousands of different varieties of tulips. This lovely spring bloomer contains tulipalin and other toxic components, which can cause stomach pain, salivation, depression, diarrhea, sweating, nausea, and vomiting. Some people also develop a skin reaction. Like other spring-flowering bulbs, the highest amount of toxins is in the tulip bulb. Pets who ingest this plant or the bulb will experience serious symptoms, including hypersalivation and vomiting.

Yews are handsome evergreen shrubs with soft needle-like leaves and pretty bright red berries. Unfortunately, the bark, leaves, and seeds of this plant contain the alkaloid taxine, which is toxic to people and pets. Ingesting the plant may cause nervousness, slow pulse, difficult breathing, abdominal pain, vomiting, and diarrhea. Yew also may cause seizures and sudden death in dogs who have ingested it or even have been playing with branches or sticks from this plant.

This attractive palm is quite common. It’s grown as a houseplant or outdoors in warm climates. However, all parts of this plant contain the toxin cycasin, with the highest concentration in the seeds. Ingestion of any part of sago palm may cause vomiting, diarrhea, seizures, permanent internal damage, or death. In pets, symptoms include vomiting, bleeding, and death.

The beautiful tall spikes of foxglove flowers are lovely in a pollinator or cottage garden. They lend an old-fashioned feel to landscape plantings. However, all parts of this plant are toxic, containing cardiac glycosides. (Interesting side note: the leaves are extracted to make digoxin, a heart medication).

Ingestion may cause nausea, vomiting, diarrhea, stomach pain, severe headache, irregular and slow pulse, tremors, cardiac arrhythmias, and even death. In pets, ingesting any part of this plant may cause cardiac arrhythmias, vomiting, diarrhea, weakness, cardiac failure, and death.